[Bug c/39036] Decimal floating-point exception flags done wrong

["joseph at codesourcery dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #6 from joseph at codesourcery dot com  2009-01-30 23:14 -------
Subject: Re:  Decimal floating-point exception flags done wrong

On Fri, 30 Jan 2009, tydeman at tybor dot com wrote:

> I consider emulation of decimal FP to be part of the compiler's job.  Part of
> that emulation is setting the FP execption flags as per IEEE-754-2008.

The implementation of decimal FP for the GNU system is partly in GCC and 
partly in (E)GLIBC (available as patches or an EGLIBC branch).  The 
implementation approach chosen is that the versions of the 
arithmetic/conversion functions that handle exceptions and rounding modes 
are included only in the libdfp included with (E)GLIBC, not in libgcc.  
(Depending on the target, copies of libm functions to handle exceptions 
and rounding modes may need including in libdfp to avoid a dependency on 
libm, and this can only be done as part of the libc/libm/libdfp 
implementation.)

So, if you want exceptions and rounding modes support for decimal FP, use 
an appropriate libc version and link against the associated libdfp.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39036